Physiologic monitoring of animals, for example, with circulatory assist devices, often requires percutaneous electrical wires and fluid-filled catheters leading to stationary power consoles and meters. Animal mobility must be restricted to prevent entanglement and disruption of these lines. Although fluid/electrical swivels are available for signal transduction, they are not capable of carrying currents large enough for power transmission. Existing swivels are limited to continuous current capacity ceiling of approximately 200 milliamps. Consequently, chronic in vivo studies have necessitated that the animal be confined to a stanchion for the duration of the experiment, or that personnel continuously observe the animal to prevent entanglement of electrical wires which hang from a hook. Furthermore, existing swivels allow only a limited number of electrical wires to be used for monitoring or current transmission.
The present invention is directed to a unique tether system which greatly increases animal mobility during long-term studies with electrically powered devices, for instance, a circulatory assist device, and provides means or a mechanism for accommodating more than ten electrical circuits, and for accommodating electrical currents in excess of 200 milliamps.
SUMMARY OF THE INVENTION
The present invention pertains to a tether system for an animal. The system is comprised of an electrically powered or monitored apparatus implanted in or connected to the animal. The electrical apparatus is powered or monitored with greater than 200 milliamps of current. There is also an area for the animal and a structure above the area. The tether system is comprised of an anchor for attachment to the structure. The tether system is also comprised of means or a mechanism for providing power to the apparatus to operate it. The anchor prevents entanglement of the power providing means for mechanism as the animal moves freely about the area. The providing means or mechanism is in electrical communication with the anchor and the apparatus. Preferably, the tether system also includes means or a mechanism for transferring fluid to and from the animal. The fluid transferring means or mechanism is fluidically connected to the anchor and the animal. Additionally, the tether system can include means or a mechanism for transmitting electrical and fluid signals from the animal. The transmitting means or mechanism is in electrical and fluidic communication with the anchor and the animal.
The present invention also pertains to a method for tethering an animal with an implanted or connected apparatus which is electrically powered. The method comprises the steps of attaching a first electrical conduction element to the apparatus connected to or implanted in the animal so the first electrical conduction element extends from an anchor attached to a structure above and remote from the animal to the animal. Then, there is the step of providing current to the apparatus to power it. Next, there is the step of allowing the animal to freely walk around the area while connected to the first electrical conduction element extending down from the anchor attached to the structure above the animal in the area.